I’mworking on a still life with western subject matter and recently went to the Eiteljorg museum. I saw this painting there by Robert Griffing and was really impressed. He used to be a commercial artist and started doing fine art focusing on historically accurate early frontiers Native Americans. He works closely with native tribes when researching historical accuracy.
I was amazed at how many commercial artists / illustrators were represented in the museum.

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Think about it. In the 20th century fine art was not painting realism. The realism that was seen Benton, Bellows, Sloan, Kent, Benton was Illustrative. Mostly done by artist who at least got their starts as illustrators. Realism never died it simply found its way onto book covers and into magazines.
My art school had about 800 students. Probably 60 who were learning some kind of realism. I worked mostly as a humorist. But I was trained to draw by having at least 12 hours a week of life drawing. Because of that I rarely needed models or reference. Everything came out of my head. As imagination or memory.
I say this to illustrate how important drawing is. Drawing from live figures. Live scenes. Especially when you are developing a sense of sense as an artist. I know everyone here just wants to paint. Drawing is the most important thing for a realist. I don't just mean capturing likeness of a fruit or a person. But understand spacial relationships, perspective, light, scale and composition.
This painting of the Native Americans is a prime example. A solid place in nature, dramatic light, character and costume. So beautifully drawn. The painting for this was relatively easy.
My teacher was a pulp magazine guy. Norman Baer.
I wasn't
The best way is to find a formal figure drawing class. Good luck. Until the masks come off. Loom is Figure Drawing for All It’s Worth. Proko. Sketching at the Mall. But nobody is at the mall.
He also specializes in Native Americans, mainly the plains tribes of the western US.
This painting depicts the Blackfoot Nations thunder pipe ceremony that takes place in the spring after the first thunderstorm.
Terpning is masterful. He’s right up there with Griffing.